This invention relates to mops, and in particular to replaceable mopheads having a plurality of strands of water-absorbent mop material.
One problem with conventional mopheads having a plurality or bundle of strands is that unless the strands are securely fastened together, and to the mop, individual strands may be pulled from the bundle during use.
Mopheads utilizing various means for securing the strands together have been developed. In one known mophead construction--exemplified by Toplitz U.S. Pat. No. 1,701,167--the bundle of strands is surrounded by a strip of web material, such as canvas, and the web material and strands are stitched together. While this construction has had considerable success, it necessitates a costly manufacturing step requiring labor, time, floor space, and stitching machinery. Further, if every strand is not stitched, or if the stitching fails, strands can be pulled out during use.
Other known mopheads rely, at least in part, on using great pressure to permanently attach the strands together. The mop strands, for example, may be clamped between a rigid plate and a bale wire as shown in McClung et al. U.S. Pat. No. 3,447,183. Alternatively, as shown in Bundenthal et al. U.S. Pat. No. 2,159,350, the strands may be secured between two channel-shaped jaw members wherein two U-shaped prongs, made of spring wire, are riveted to the first jaw. The prongs' legs project through slots in the first jaw and through corresponding slots in the second jaw. While the jaws are pressed together under great force, the legs are folded over to secure the mop strands between the jaws.
As a further alternative, exemplified by Sellesi U.S. Pat. No. 3,328,822, the strands may be secured between two plates. The first plate may have attached a plurality of rigid cylinders. Each cylinder has a tip of diameter greater than both the diameter of the cylinder and the diameter of a corresponding hole in the second plate. Each tip is forced through the corresponding hole such that the tips overlap the backside of the second plate and thus prevent the prongs from withdrawing from the holes. This secures the two plates together with the mop strands therebetween.
Another known mophead, shown in Martin U.S. Pat. No. 2,492,232, combines the use of the stitched web and pressure by clamping the strands about the webbed section between a bale and a plate. While this construction allows for replaceability of the mop strands, it does not adequately solve the problem of securely fastening the strands at a low cost.
Another mophead known in the art (see McClellan U.S. Pat. No. 3,512,203) is formed by injecting a plastic material into a mold in which the strands have been inserted. The plastic completely penetrates the strands and forms a water impervious barrier about the mid portion of the strands.
Yet another known mophead (see Disko U.S. Pat. No. 4,114,224) uses a nonwoven web of material rather than fibrous strands. The material has holes cut in it to fit over or about a central post for holding the material in place.
Except for mopheads having stitched webbing, the securing means must exert great clamping pressure on the strands either while the strands are being affixed in place, or continuously in order to keep the strands in place, or both. Conventional mopheads having metal pieces suffer the risk that those pieces with which the strands are mechanically connected may weaken significantly over time and with repeated use. Further, the metal construction may scratch floors or damage furniture, and also has a tendency to corrode, which accelerates the effects of wear. Other mopheads constructions require injection of plastic under considerable pressure into the strands within special insert molding equipment.
None of the above-mentioned mophead constructions can be made utilizing the low-cost, high-production-rate techniques necessary to produce disposable mopheads which will perform as well as, if not superior to, any mops not having replaceable mopheads, or any mops having replaceable strands.
It is therefore an object of this invention to provide a disposable mophead which is relatively inexpensive to manufacture and superior in performance, and in which the water-absorbent material is securely held together by relatively small mechanical forces.
It is another object of this invention to provide a throw-away plastic mophead which permanently secures water-absorbent material without the need for excessive initial or continuous clamping pressure.